摘要
以硅酸乙酯(TEOS)和纳米镍粉为主要原料,通过溶胶-凝胶法制备了SiO2包覆镍核壳结构纳米复合粒子。利用X射线衍射(XRD)、高分辨透射电镜(HRTEM)和选区电子衍射(SAED)、X射线能量色散分析谱仪(EDS)和振动试样磁强计(VSM)等测试手段对样品的晶体结构、形貌、组成元素和磁学性能等特征进行了表征。结果表明:SiO2以非晶态的形式包覆在纳米镍粒子表面,形成了明显的核壳结构,降低了纳米粉体的团聚现象。颗粒大多呈球形或椭球形,粒径分布在20～80 nm范围,平均粒径为30 nm,镍粒子外碳层的厚度为4～6 nm。包覆后的粉体由于SiO2的存在,饱和磁化强度与剩磁比纳米镍粉降低,矫顽力升高。
SiO2 encapsulated Ni core-shell structure composite nanoparticles were prepared by the sol-gel method using TEOS and Ni nanoparticles as the main raw materials. The crystal structure,morphology,constituent elements and magnetic properties of the products were investigated by means of X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),corresponding electron diffraction(SAED),X-ray energy dispersive spectrometry(EDS) and the vibrating sample magnetometer(VSM). The results show that SiO2 encapsulated Ni nanoparticles with clear core-shell structure,the core of the particles is face centered cubic structure Ni,and the shell of the particles is noncrystal silica and it prevents the nanoparticles from agglomerating. The particles are scattered homogeneously in spherical or ellipsoidal shapes,The dimeter of the particles ranges from 20 to 80 nm,with an averaged value about 30 nm,and the thickness of the shells is about 4-6 nm. After coating the saturation magnetization and remnant magnetism decreases,while the coercivity increases.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第S2期28-31,共4页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金资助项目(51261015)
甘肃省高等学校基本科研项目(1110ZTC138)
关键词
SIO2
核壳结构
纳米复合颗粒
微观结构
磁滞回线
SiO2
core-shell structure
composite nanoparticles
microstructure
hysteresis loop
